Lewis & Short

permissĭo, ōnis, f. [permitto].

  1. I. In gen., a giving up, yielding, ceding to another’s will and pleasure; an unconditional turrender, Liv. 37, 7.
    1. B. A rhet. figure, in which a thing is committed to the decision of one’s opponent, permission, Auct. Her. 4, 29, 39; Quint. 9, 2, 25; 9, 3, 90.
  2. II. In partic., leave, permission (very rare for permissus): mea permissio mansionis tuae, Cic. Q. Fr. 3, 1, 3, § 9: sine permissione Dei diabolus nocere non potest, Ambros. in Luc. 7, 115.